Reconfigurable control architectures and algorithms for electric vehicle wireless energy transfer systems

ABSTRACT

A control architecture for electric vehicle wireless power transmission systems that may be segmented so that certain essential and/or standardized control circuits, programs, algorithms, and the like, are permanent to the system and so that other non-essential and/or augmentable control circuits, programs, algorithms, and the like, may be reconfigurable and/or customizable by a user of the system. The control architecture may be distributed to various components of the wireless power system so that a combination of local or low-level controls operating at relatively high-speed can protect critical functionality of the system while higher-level and relatively lower speed control loops can be used to control other local and system-wide functionality.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional patentapplication 61/533,281 filed Sep. 12, 2011 and U.S. provisional patentapplication 61/566,450 filed Dec. 2, 2011.

BACKGROUND

Field

This disclosure relates to wireless energy transfer and methods forcontrolling the operation and performance of electric vehicle wirelesspower transmission systems.

Description of the Related Art

Energy or power may be transferred wirelessly using a variety of knownradiative, or far-field, and non-radiative, or near-field, techniques asdetailed, for example, in commonly owned U.S. patent application Ser.No. 12/613,686 published on May 6, 2010 as US 2010/010909445 andentitled “Wireless Energy Transfer Systems,” U.S. patent applicationSer. No. 12/860,375 published on Dec. 9, 2010 as 2010/0308939 andentitled “Integrated Resonator-Shield Structures,” U.S. patentapplication Ser. No. 13/222,915 published on Mar. 15, 2012 as2012/0062345 and entitled “Low Resistance Electrical Conductor,” U.S.patent application Ser. No. 13/283,811 published on ______ as ______ andentitled “Multi-Resonator Wireless Energy Transfer for Lighting,” thecontents of which are incorporated by reference.

Recharging the batteries in full electric vehicles currently requires auser to plug a charging cord into the vehicle. The many disadvantages ofusing a charging cord, including the inconvenience, weight, andawkwardness of the cord, the necessity of remembering to plug-in andun-plug the vehicle, and the potential for cords to be stolen,disconnected, damaged, etc., have motivated makers of electric vehiclesto consider wireless recharging scenarios. Using a wireless powertransmission system to recharge an electric vehicle has the advantagethat no user intervention may be required to recharge the vehicle'sbatteries. Rather, a user may be able to position a vehicle near asource of wireless electricity and then an automatic control system mayrecognize that a vehicle in need of charge is present and may initiate,sustain, and control the delivery of wireless power as needed.

One of the advantages of wireless recharging of electric vehicles isthat the vehicles may be recharged using a variety of wireless powertechniques while conforming to a variety of performance criteria. Thevariety of available wireless power techniques and acceptableperformance criteria may present challenges to system designers who maylike to provide for interoperability between different wireless sourcesand wireless devices (usually integrated in the vehicles) and at thesame time differentiate their products by offering certain enhancedfeatures. Therefore there is a need for an electric vehicle wirelesspower system control architecture that may ensure safe, efficient andreliable performance that meets certain industry performance standardsand that offers designers and users of the end-system the opportunity tocustomize their systems to offer differentiated and enhanced features tothe drivers of their vehicles.

SUMMARY

This invention relates to a control architecture for electric vehicle(EV) wireless power transmission systems that may be segmented so thatcertain essential and/or standardized control circuits, programs,algorithms, and the like, are permanent to the system and so that othernon-essential and/or augmentable control circuits, programs, algorithms,and the like, may be reconfigurable and/or customizable by a user of thesystem. In addition, the control architecture may be distributed tovarious components of the wireless power system so that a combination oflocal or low-level controls operating at relatively high-speed canprotect critical functionality of the system while higher-level andrelatively lower speed control loops can be used to control other localand system-wide functionality. This combination of distributed andsegmented control may offer flexibility in the design and implementationof higher level functions for end-use applications without the risk ofdisrupting lower level power electronics control functions.

The inventors envision that the control architecture may comprise bothessential and non-essential control functions and may be distributedacross at least one wireless source and at least one wireless device.Non-essential control functions may be arranged in a hierarchy so that,for example, more sophisticated users may have access to more, ordifferent reconfigurable control functions than less sophisticatedusers. In addition, the control architecture may be scalable so thatsingle sources can interoperate with multiple devices, single devicescan interoperate with multiple sources, and so that both sources anddevices may communicate with additional processors that may or may notbe directly integrated into the wireless power charging system, and soon. The control architecture may enable the wireless power systems tointeract with larger networks such as the internet, the power grid, anda variety of other wireless and wired power systems.

An example that illustrates some of the advantages of the distributedand segmented architecture we propose is as follows. Imagine that anoriginal equipment manufacturer (OEM) of an EV wireless powertransmission system may need to provide a system with certain guaranteedand/or standardized performance such as certain end-to-end transmissionefficiency, certain tolerance to system variations, certain guaranteesfor reliability and safety and the like. An integrator who integratesthe wireless power transmission system into an electric vehicle may wishto distinguish their vehicle by guaranteeing higher efficiency and/ormore robust safety features. If the control architecture is structuredin such a way that the integrator can set certain thresholds in thecontrol loops to ensure higher efficiency and/or may add additionalhardware (peripherals) to the system to augment the existing safetyfeatures, then the integrator may be able to offer significant productdifferentiation while also guaranteeing that basic system requirementsand/or standards are met. However, if the control architecture is notsegmented to offer some reconfigurable functions while protecting thecritical functions of the wireless power system, changing certaincontrol loops and/or adding additional hardware may disrupt the requiredlow-level power delivery, reliability, and safety performance of thesystem.

Note that the inventive control architecture described in thisdisclosure may be applied to wirelessly rechargeable electric vehiclesusing traditional inductive and magnetic resonance techniques. Becausethe performance of traditional inductive wireless power transmissionsystems is limited compared to the performance of magnetic resonancepower transmission systems, the exemplary and non-limiting embodimentsdescribed in this disclosure will be for magnetic resonance systems.However, it should be understood that where reference is made to sourceand device resonators of magnetic resonance systems, those componentsmay be replaced by primary coils and secondary coils in traditionalinductive systems. It should also be understood that where an exemplaryembodiment may refer to components such as amplifiers, rectifiers, powerfactor correctors and the like, it is to be understood that those arebroad descriptions and that amplifiers may comprise additional circuitryfor performing operations other than amplification. By way of examplebut not limitation, an amplifier may comprise current and/or voltageand/or impedance sensing circuits, pulse-width modulation circuits,tuning circuits, impedance matching circuits, temperature sensingcircuits, input power and output power control circuits and the like.

In one aspect of the invention a wireless energy transfer system mayinclude a segmented control architecture. The wireless system mayinclude a primary controller and a user configurable secondarycontroller that is in communication with the primary controller. Theprimary controller may be configured to perform the essential controlfunctions for the wireless system. The essential control functions ofthe primary controller may include maintaining the wireless energytransfer operating safety limits. The primary controller may monitor andcontrol the voltage and currents on the components of the wirelessenergy transfer system. The user configurable secondary controller maybe configured to allow adjustment of non-safety critical parameters ofthe system such as adjusting the maximum power output, scheduling of onand off times, adjusting the frequency of energy transfer, and the like.In accordance with exemplary and non-limiting embodiments the primaryand secondary controllers may be implemented on separate hardware orprocessors. In other exemplary embodiments the primary and secondarycontrollers may be virtual controllers and implemented on the samehardware.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 shows exemplary components in an electric vehicle wireless powertransfer system.

FIG. 2 shows an exemplary charging system control diagram for anelectric vehicle wireless power transfer system. This exemplaryembodiment shows that system performance may be monitored with a laptopthrough the wireless and/or wired “Debug” and “Status” ports.

FIG. 3A shows a notional state diagram of the system charging cycle.Activation states are denoted by the rectangles. Conditional statementsthat enable transitions between states are enclosed in square brackets.Fault detection on either side results in both sides entering theAnomaly state.

FIG. 4 shows an exemplary charging cycle use-case.

FIG. 5 shows a Sequence Diagram for interaction between a source and anelectric vehicle during an exemplary charging engagement.

FIG. 6 shows an exemplary embodiment of power factor corrector controlloops.

FIG. 7 shows an exemplary embodiment of source amplifier control loops.

FIG. 8 shows an exemplary embodiment of device rectifier control loops.

FIG. 9 shows exemplary interfaces to and from an application sourceprocessor.

FIG. 10 shows exemplary interfaces to and from an application deviceprocessor.

FIG. 11 shows exemplary interfaces to and from an amplifier controller.

FIG. 12 shows exemplary interfaces to and from a rectifier controller.

FIG. 13 shows exemplary ASP control parameters.

FIG. 14 shows exemplary ADP control parameters.

FIG. 15 shows exemplary amplifier control parameters.

FIG. 16 shows exemplary rectifier control parameters.

DETAILED DESCRIPTION

This disclosure describes exemplary reconfigurable system controlconcepts for electric vehicle wireless power transmission systems. Ingeneral, an electric vehicle (EV) may be any type of vehicle such as acar, a boat, a plane, a bus, a scooter, a bike, a cart, a movingplatform, and the like that comprises a rechargeable battery. Thewireless power transmission system may provide power to the batterycharging circuit of the electric vehicle and/or it may power the vehicledirectly. Wireless power may be provided to the vehicle while it isstationary or while it is moving. The power provided wirelessly torecharge the vehicle battery may be more than 10 Watts (W), more than100 W, more than a kilowatt (kW), more than 10 kW, and/or more than 100kW, depending on the storage capacity and power requirements of thevehicle. In some exemplary low power embodiments, fewer control loopsand/or less distributed and/or less segmented control architectures maybe sufficient to ensure safe, reliable and efficient operation of thewireless power transmission system. In some exemplary high powerembodiments, redundant control loops and/or multi-level controlarchitectures may be required to realize safe, reliable and efficientoperation of the wireless power transfer system.

This disclosure describes certain control tasks that may be necessaryfor enabling an electric vehicle charging engagement using a wirelessenergy transfer system as well as potential control loops, states, andsequences of interactions that may govern the performance of the system.The proposed control architectures and tasks may enable transactionmanagement (e.g. billing, power origination identification, direction ofpower flow), integration with vehicle electronics, and higher levelcontrol tasks for system operation, communications, and anomalyresolution. Throughout this disclosure we may refer to certainparameters, signals, and elements as being variable, tunable,controllable, and the like, and we may refer to said parameters, signalsand elements as being controlled. It should be understood that systemparameters, signals and elements may be controlled using hardwarecontrol techniques, software control techniques, and/or a combinationsof hardware and software control techniques, and that these techniquesand the circuits and circuit elements used to implement them may bereferred to as controllers and/or system controllers.

A block diagram of an exemplary wireless electric vehicle (EV) batterycharging system is shown in FIG. 1. In this exemplary embodiment thesystem is partitioned into a source module and a device module, witheach module consisting of a resonator and module control electronics.The source module may be part of a charging station and the devicemodule may be mounted onto a vehicle. Power may be wirelesslytransferred from the source to the device via the resonators. Closedloop control of the transmitted power may be performed through anout-of-band communications link between the source and the device, anin-band communications link between the source and the device, or acombination of in-band and out-of-band signaling protocols between thesource and device. In some exemplary and non-limiting embodiments, someor all of the system control functions may be realized in a computer,processor, server, network node and the like, separated from the sourceand device modules. In some exemplary embodiments, the system controllermay control more than one source, more than one device and/or more thanone system.

A wireless power transmission system for electric vehicle charging canbe designed so that it may support customization and modifications ofthe control architecture. Such customizations and modifications may bereferred to as reconfigurations, and an architecture designed to supportsuch reconfigurations may be referred to as reconfigurable. In someexemplary and non-limiting embodiments, the control architecture may berealized in physically separate components, such as multiplemicroprocessors and some functions, processes, controls, and the likemay be reconfigurable by a user of the system, and some may not. In someexemplary and non-limiting embodiments, the reconfigurable portions ofthe control architecture may be implemented in certain chips,micro-processors, field programmable gate arrays (FPGAs), PeripheralInterface Controllers (PICs), Digital Signal Processors (DSPs),Application Specific Processors (ASPs), and the like. In an exemplaryembodiment, some reconfigurable portions of the control architecture mayreside in ASPs which may be 32-bit microcontrollers with C-languagesource code. In some exemplary and non-limiting embodiments, the controlcode may reside on a single processor and a user may have permission toaccess certain portions of the code. In exemplary and non-limitingembodiments, both hardware and software segmentation of the controlfunctions of an EV wireless power transmission system are contemplatedin this disclosure.

In an exemplary embodiment, the system architecture may support ASPs inthe source and device modules and these processors may be referred to asApplication Source Processors (ASP) and the Application DeviceProcessors (ADP). This control architecture may enable different usersand/or manufacturers of different vehicles and vehicle systems to beable to add to the source code or customize it for integration withtheir vehicles and/or in their intended applications. Throughout thisdisclosure we may use the terms processor, microprocessor, controller,and the like to refer to the ASPs described above and any suitable typeof microprocessor, field programmable gate array (FPGA), PeripheralInterface Controller (PIC), Digital Signal Processor (DSP), and thelike, that is known to one of skill in the art. In exemplary andnon-limiting embodiments, the ASP and ADP may be used to present certainsystem parameters and control points to wireless power system designersand/or vehicle integrators and to restrict access to certain othersystem parameters and control points. For example, certain controlfeatures may be essential to ensure proper and/or safe operation of awireless power transmission system, and such control features may beimplemented in hardware only loops and/or in physically separatedmicrocontrollers and/or in restricted portions of the ASPs so that theymay not be customized and/or modified by certain users of the systems.

In exemplary and non-limiting embodiments, one, some or all of thecontrol functions of the wireless power system may be based on hardwareimplementations and/or may be hard-coded into the system and/or may besoft-coded into the system but with restricted access so that onlyselect and verified users may make changes to the various codes,programs, algorithms and the like, that control the system operation.

Note that whether or not the functionality associated with the ASPs inthis exemplary embodiment are realized in physically separate hardwarecomponents or in isolated sections of code, the concept of partitioningthe control plane into at least source-side and device-side functionsand into at least high-level and low-level functions is what enables thereconfigurability of system operation while guaranteeing certain safety,reliability and efficiency targets are met. The distribution andsegmentation of the control plane allows flexibility in the adaptationof the higher level functions for vehicle designer and/or end userapplications without the risk of disrupting the operation of the lowlevel power electronics control functions. In addition, the partitioningof the control plane allows for variable control loop speeds; fast andmedium speeds for the low level critical hardware control functions ofthe power electronics as well as slower control loop speeds for the highlevel designer and/or end user control loops.

As time goes on, this partitioned control plan architecture may scale toadjust to and support more functionality and applications, at the sametime it may be adapted to changing hardware requirements andstandardized requirements for the safe and efficient delivery of power.For example, the fast and medium speed control loops may be adapted tosupport wireless power transmission at a range of operating frequenciesand over a range of coupling coefficients, both of which may eventuallybe set by regulatory agencies. Also, users may access and customize thehigher level control functions to implement functionality that mayinclude, but may not be limited to:

-   -   Programming an EV wireless source to connect through a wired        internet connection in the source, or through Wi-Fi or the        cellular network to display certain source attributes such as        what type of resonator it comprises, how much energy it can        supply, what the price is for the energy it supplies (this price        may change during the day, being less expensive at night when        the peak demand for electricity is lower, or it may change        seasonally, costing more when the temperature is hot and air        conditioning requirements are stressing the electrical suppl),        where the energy it supplies originates from (renewables, coal        plant, etc.), does this source require a reservation, if it        requires a reservation, when are the free times that can be        reserved, what type of FOD detectors does it deploy, what is the        status of the source (has FOD been detected and needs to be        cleaned off before charging can be initiated, or has FOD been        detected and so the source can only supply a limited amount of        power).    -   Programming an EV wireless power transfer system so that it may        connect to a communication network and may contact the vehicle        user to report the status of the charge cycle and to report when        charging is complete or when charging has been interrupted or        that the source and/or device are in an anomaly state.    -   Programming an EV wireless power transfer system so that power        is transmitted from the device back to the grid and managing the        transaction so that the vehicle user is paid for supplying that        energy.    -   Programming a user interface in the vehicle so that information        regarding the position of the vehicle resonator relative to the        source resonator can be relayed to the driver of the vehicle.        The relative position information may be used to give the        vehicle driver an estimate of the wireless transfer efficiency        with the vehicle in its current location and may offer the        driver a chance to change the parking position to improve the        wireless system performance. The user interface may include        visible, audible, vibrational and the like feedback to help the        driver reposition the vehicle.    -   Programming an EV wireless power transfer system so that it        communicates with an automatic vehicle parking capability        resident on the vehicle and parks the vehicle in a position that        is optimized for wireless power transfer efficiency. Other        commands that may be communicated from the EV wireless power        transmission system to the vehicle may include commands to        control the active suspension of the vehicle to raise or lower        the vehicle relative to the source to optimize wireless power        transfer.

FIG. 2 shows an exemplary charging system control diagram for anelectric vehicle wireless power transfer system. In this block diagram,the source components of the system are shown on the left side of thediagram and the device (or vehicle) components of the system are shownon the right.

In exemplary and non-limiting embodiments, AC line power may flow into apower factor corrector (PFC) and provide a DC voltage to a switchingamplifier. In exemplary and non-limiting embodiments, the DC voltageprovided to the switching amplifier may be variable and may becontrolled. In exemplary and non-limiting embodiments, a DC voltage maybe provided to the amplifier from a DC source of power (not shown) suchas a solar cell, a battery, a fuel cell, a power supply, a supercapacitor, a fly wheel, and the like. In exemplary and non-limitingembodiments, the DC voltage from a DC power source may be variable andmay be controlled.

The switching amplifier in the source of an electric vehicle wirelesspower transmission system may be any class of switching amplifierincluding, but not limited to, a class D amplifier, a class E amplifierand a class D/E amplifier. The switching frequency of the amplifier maybe any frequency and may preferably be a frequency previously identifiedas suitable for driving inductor coils and/or magnetic resonators. Inexemplary and non-limiting embodiments, the switching frequency may bebetween 10 kHz and 50 MHz. In exemplary and non-limiting embodiments,the frequency may be approximately 20 kHz, or approximately 44 kHz, orapproximately 85 kHz, or approximately 145 kHz, or approximately 250kHz. In exemplary and non-limiting embodiments, the switching frequencymay be between 400 and 600 kHz, between 1 and 3 MHz, between 6 and 7MHz, and/or between 13 and 14 MHz. In exemplary and non-limitingembodiments, the frequency of the switching amplifier may be tunable andmay be controlled.

In exemplary and non-limiting embodiments, an amplifier controller maymanage the electronic components in the amplifier and/or in the PFCand/or in the DC power supply (not shown). The amplifier controller maymonitor and control so-called local control loops and local interlocksfor conditions such as over voltage/current in the source electronics,ground-fault circuit interrupt in the source electronics, andout-of-specification AC impedance changes at the source coil. Inexemplary and non-limiting embodiments, the amplifier controller mayreact quickly to shut the system down safely in response to a variety ofset point violations. The amplifier controller may expose registers forset-points and control to the ASP through an inter-integrated circuit(I²C) interface, referred to in the figure as the “User Interface”. Theamplifier controller may also have a watchdog timer (or heartbeat input)to detect if communication with the Application Source Processor (ASP)or with the vehicle has been lost.

In an exemplary embodiment, the ASP may provide high-level control ofthe source electronics and the overall system charging cycle. Forexample, the ASP may interface with a foreign-object-debris (FOD)detector that monitors the source module for the presence of FOD and/orexcessive temperature. The ASP may be connected to an in-band and/orout-of-band communications link that may communicate with thevehicle-side application device processor (ADP) to provide closed loopcontrol of the charging cycle.

In an exemplary embodiment on the vehicle side (also called the deviceside), a rectifier controller may perform low-level and local functionsfor the device side that are analogous to those described for the sourceside. Again, an I²C interface may be provided for interfacing with ahigher-level ADP. The ADP could be configured to connect via a CAN-busor equivalent to a battery manager that may control the power deliveredfrom the rectifier to the battery, vehicle engine or any time of powerstorage or management system on the vehicle. The ADP could communicatethat information to the source-side ASP which, in turn, could adjust thepower settings on the amplifier controller.

In an exemplary embodiment, the control architecture may be partitionedinto three types of control loops: fast, medium and slow. The fastcontrol loops may be for time critical functions (less than 1-mslatency) and may be either hardware control loops or interrupt-drivenlow-level software modules. Medium-speed control loops may be forfunctions that operate under real-time software control (<500-mslatency). Slow control loops (>500 ms latency) may be for functions withlow bandwidth requirements or functions with unpredictable latency, forexample, a 802.11-family wireless communication link.

FIG. 2 shows the three types of control loops as they may be applied toan exemplary electric vehicle wireless power transmission system. Inexemplary and non-limiting embodiments, embedded software portions ofthe control loops may be partitioned between the amplifier and rectifiercontrollers and the processors (ASP and ADP). The amplifier andrectifier controllers may handle the hardware control and the operationof high-power and/or sensitive electronics components. The ASPs mayhandle the system control loop and may provide interfaces to externalperipherals, such as FOD detectors, communication links, monitoringequipment, and other vehicle and source electronics.

In exemplary and non-limiting embodiments, some of the functions thatmay operate under fast feedback-loop control may be based on hardwareset-points and/or on software (programmable) set-points which mayinclude but may not be limited to over-current protection, over-voltageprotection, over-temperature protection, voltage and current regulation,transistor shoot-through current in the switching amplifier, GFCI(ground fault circuit interrupt) and critical system interlocks. Inexemplary and non-limiting embodiments, system events that may causedamage to the system itself or to a user of the system in a short periodof time may be detected and reacted to using fast feedback-loop control.

In exemplary and non-limiting embodiments, some of the functions thatmay operate under medium-speed feedback loops may include, but may notbe limited to temperature set-point violations, impedance set points todeclare an out-of-range condition for the source coil impedance, FODdetection, monitoring for violations of the minimum efficiency setpoint, local power control in the source-side electronics and processorheartbeat monitoring (i.e. watchdog-timer expiration). In exemplary andnon-limiting embodiments, system events that may cause damage to thesystem itself or to a user of the system in a medium period of timeand/or that may cause the system to operate in an undesirable state(e.g. low efficiency) may be detected and reacted to using mediumfeedback-loop control.

In exemplary and non-limiting embodiments, some of the functions thatmay operate under relatively slow-speed loop control may include but maynot be limited to system power control loop (e.g. for executing abattery-charging profile), charge request/acknowledge messages betweenvehicle(s) and source(s), system start/stop messages, system levelinterlocks, RF communications link heartbeat monitoring (i.e.watchdog-timer expiration), status/GUI updates to a diagnostic laptopand messages for source/vehicle transactions, authentication andconfiguration. In exemplary and non-limiting embodiments, system eventsthat may cause damage to the system itself or to a user of the system ina long period of time and/or that may cause the system to operate in anundesirable state (e.g. low efficiency, insufficient information forclosing a transaction) may be detected and reacted to using slowfeedback-loop control.

FIG. 3 shows a notional state diagram of the system charging cycle. Thediagram shows examples of state machines that may be running on the ASPsin the source side and the vehicle side of the EV wireless powertransmission system. Potential activation states are shown within eachrectangle and potential conditional statements that must be satisfied toenable transitions between states are enclosed in square brackets. Inexemplary and non-limiting embodiments, in-band, out-of-band, and/or acombination of in-band and out-of-band wireless communication linksbetween the source and the vehicle may provide for messaging andsynchronization. In exemplary and non-limiting embodiments, thecommunications required to implement control functions, processes andthe like may piggy-back on existing or native communication systems inand around the vehicle. For example, messages may be passed amongst thesource(s), the vehicle(s), and any additional networked component(s)using CAN-bus equipment and protocols, Bluetooth equipment andprotocols, Zigbee equipment and protocols, 2.4 GHz radio equipment andprotocols, 802.11 equipment and protocols, and/or any proprietarysignaling scheme equipment and protocols implemented by the user.

For charging electric vehicles that may be described in the standardsproposed by the Society of Automotive Engineers (SAE), the chargingengagement between the source and vehicle for wireless charging may besimilar to that described by SAE J1772 for wired charging, withadditional steps added to support wireless charging.

An exemplary use-case for stationary EV charging involving the operationof the control system is shown in the table in FIG. 4. In an exemplaryembodiment, a wireless source may be powered and available to supplypower to a wireless device and may be referred to as being in theAvailable state. A wireless source may constantly, periodically,occasionally and/or in response to some trigger, broadcast informationregarding any of its availability, position, location, power supplycapabilities, power costs, power origination (solar, coal burning plant,renewable, fossil fuel, etc.), resonator type, resonator cross-section(so that a vehicle may calculate and/or look-up an expected couplingcoefficient with the source), and the like. A vehicle may be receivinginformation broadcast by wireless power sources and may search for anavailable wireless power source, with matching hard-wired and/or useselectable features, over which it may park. The vehicle's communicationlink may be active so that it is in the Searching state. If vehicleidentifies a suitable wireless source, it may approach that source andinitiate two way communications with the source so that the source anddevice side control electronics can exchange configuration information.In an exemplary embodiment, when sufficient information has beenexchanged by the source and the device, and when the vehicle resonatorhas been positioned substantially in the near vicinity of the sourceresonator, the source and vehicle sides may switch to their Dockingstates.

In an exemplary Docking state, both source and device may confirm theircompatibility and an alignment error signal may be provided to thevehicle driver so that he/she can maneuver the car into proper position.Once in position, the drive train of the vehicle may be disabled and thesource and device may enter the Coupled state.

In an exemplary embodiment, a ‘Charge Request’ may be sent from thevehicle—either automatically or driver initiated, and may be received bythe source. In the Coupled state, there may be further exchange ofconfiguration information, safety checks, and the like. Once those arepassed, both sides may enter the Ready to Charge state.

In an exemplary embodiment, in the Ready to Charge state, the vehiclemay issue a ‘Start Charging’ command and both the source and the vehiclemay enter the Charging state as the source power ramps up. In theCharging state, both source and vehicle may perform monitoring andlogging of data, faults, and other diagnostics. Logging and monitoringmay include, but may not be limited to an event loop that looks forhazardous and/or restricted Foreign Object Debris (FOD), overloads,unexpected temperature and/or efficiency excursions, and otherasynchronous events.

In exemplary and non-limiting embodiments, hazard and/or restrictedobject detection that occurs in the source during any of the poweredstates may cause the source to switch into its Anomaly state. Ifwireless communication is still working, the vehicle may be notified andmay also drop into its Anomaly state. If wireless communication is down,the vehicle may enter its Anomaly state because it didn't ask for thewireless power to be shut down and because the wireless communicationswatchdog timer expires.

In an exemplary embodiment, where the vehicle has entered the Anomalystate, state, the vehicle may send a message to the source that resultsin the source entering its Anomaly state.

In an exemplary embodiment, where the source has entered the Anomalystate, the source may send a message to the vehicle that results in thevehicle entering its Anomaly state.

In an exemplary embodiment, the source and/or vehicle may automaticallybegin a process for handling or disposition of the anomaly. The processmay involve the source and vehicle exchanging health and statusinformation to help discover the cause of the anomaly. Once the cause isdetermined, the source and vehicle may select a pre-planned action thatcorresponds to the cause. For example, in the event that detection offoreign object debris caused the anomaly, the source may reduce thepower transfer level to a safe level where the foreign object debrisdoes not overheat. In another example, in the event that the loss of RFcommunication was the cause, the source may stop power transfer until RFcommunication is re-established. In exemplary and non-limitingembodiments, where one or both sides of the system may have entered theanomaly state, the system may automatically communicate to a user thatthe system is in its Anomaly state. Communication may occur over theinternet, over a wireless network, or over another communications link.

In an exemplary embodiment, under normal operating conditions, chargingmay end when the vehicle sends a stop-charging (DONE) command to thesource. The source may immediately de-energize.

In this exemplary embodiment, after de-energizing, the source may returnto the coupled state and may notify the vehicle of its state change. Thevehicle may switch to the Coupled state and may receive additionalinformation about the charge engagement from the source. At this point,the vehicle may either stay put or it may depart. Once the source sensesthat a vehicle has departed, it may return to the Available state.

Not explicitly shown the figures are exemplary control loops that mayperform system safety and hazard monitoring, as well as localized FODdetection, for example. There a many ways a FOD detector might be usedincluding; prior to a source declaring itself Available, it may runthrough a series of diagnostic tests including FOD detection, in theDocking and in the Coupled states, the FOD detector could check forpotentially hazardous debris falling off of a vehicle and onto a sourceresonator, and before entering the Ready to Charge state, a FOD detectorreading may be part of a final safety check. In exemplary andnon-limiting embodiments, monitoring for FOD may occur during theCharging state. In exemplary and non-limiting embodiments, one, some orany anomalies or failed safety checks may turn down or shut down theamplifier and put both sides (source and vehicle) into their Anomalystates, where additional diagnostics can be safely performed.

FIG. 5 shows another representation of some potential steps if asequence of interactions in an exemplary embodiment of an EV wirelesspower transfer system. The diagram shows exemplary steps from thecharging sequence described above following Unified Modeling Language(UML) conventions:

-   -   Time flows in the downward direction    -   The vertical bars under each side represent activation of        different states    -   Arrows with solid lines indicate requests    -   Arrows with dashed lines indicate responses    -   Full arrow heads represent synchronous messages    -   Half arrow heads represent asynchronous messages    -   Arrows entering the diagram from off the page represent user        actions        Note that the diagram is not intended to show every message in        the exemplary engagement just some examples helpful to        understanding the interaction.

In exemplary embodiments of electric vehicle wireless power systems, avariety of control loops may be implemented to govern the operation ofthe wireless charging and/or powering of the electric vehicle. Someexemplary control loops for the exemplary system shown in FIG. 2 aredescribed below. The control loops described below may be sufficient forsome systems or they may need to be modified or added to ensure properoperation of other systems. The description of control loops should notbe interpreted as complete, but rather illustrative, to describe some ofthe issues considered when deciding whether system control loops mightbe fast, medium or slow in their response time, and whether or not theyshould be user reconfigurable.

In an exemplary EV wireless power transfer system, a power factorcorrector may convert an AC line voltage to a DC voltage for the source.It may provide active power factor correction to the line side and mayprovide a fixed or variable DC voltage to the source amplifier. Controlof a power factor corrector may be performed through a combination ofhardware circuits and firmware in the amplifier controller. For examplehardware circuits may be used to control against transient orshort-duration anomalies, e.g. exceeding hard set-point limits such aslocal currents or voltages exceeding safety limits for circuitcomponents, such as power MOSFETs, IGBTs, BJTs, diodes, capacitors,inductors, and resistors, and firmware in the amplifier controller maybe used to control against longer duration and slower developinganomalies, e.g. temperature warning limits, loss of synchronization ofswitching circuitry with the line voltage, and other system parametersthat may affect power factor controller operation.

In this exemplary embodiment, an amplifier may provide the oscillatingelectrical drive to the wireless power system source resonator. Hardwarecircuits may provide high-speed fault monitoring and processing. Forexample, violations of current and voltage set points and amplifierhalf-bridge (H-bridge) shoot-through may need to be detected within lessthan one millisecond in order to prevent catastrophic failures of thesource electronics.

On a medium timescale, the amplifier controller may monitor theimpedance of the source coil and may react to out-of-range impedanceconditions in less than 500 ms. For example, if the impedance is tooinductive and out-of-range, the efficiency of power transfer may bereduced and the system may turn down or shut down to prevent componentsfrom heating up and/or to prevent inefficient energy transfer. If theimpedance is inductive, but low and out of range, the system may reactas when the resonator is too inductive, or it may react differently, ormore quickly, since transitioning from an inductive load to a capacitiveload may damage the source electronics. In exemplary and non-limitingembodiments, a hardware circuit may be used to sense if the load theamplifier is driving has become capacitive and may over-ride otherslowed control loops and turn down or shut down the source to preventthe unit from becoming damaged.

In exemplary and non-limiting embodiments, system-level powerrequirements may be determined on the vehicle side and may be fed backfrom the ADP to the ASP. Over I2C, the ASP may request that theamplifier controller increment or decrement the power from the amplifierfor example. The bandwidth of the power control loop may be limited bythe latency in the wireless link and by the latency in communicationbetween the ADP and the battery manager.

In exemplary and non-limiting embodiments, a rectifier may convert theAC power received from the device resonator to DC output power for thevehicle, vehicle battery or battery charger. A monitoring circuit forthe rectifier output power, current and or voltage, as well as for thebattery charge state may provide the feedback for closed-loop control ofthe system's power transfer. The rectifier may control the outputvoltage to maintain it within the range desired by the batterymanagement system. Additional fault monitoring and an interface tovehicle charging control processes may be provided by the ADP.

In an exemplary embodiment, a rectifier module may comprise afull-bridge diode rectifier, a solid-state switch (e.g. double pole,single throw (DPST) switch), and a clamp circuit for over-voltageprotection. Under normal operation, the full-bridge rectifier may sendDC power through the closed switch and the inactive clamp circuit to thebattery system. If the battery system needs more current, it may requestit from the ADP which may forward the request to the ASP on the sourceside. If the battery needs less current, the corresponding request maybe made. The speed with which these conditions must be detected,communicated, and acted upon may be determined by how long the systemcan safely operate in a non-ideal mode. For example, it may be fine forthe system to operate in a mode where the wireless power system isproviding too little power to the vehicle battery, but it may bepotentially hazardous to supply too much power. The excess powersupplied by the wireless source may heat components in the resonator,clamp circuit and/or battery charge circuit. The speed of the feedbackcontrol loop may need to be fast enough to prevent damage to thesecomponents but may not need to be faster than that if a faster controlloop is more expensive, more complex, and/or less desirable for anyreason.

In exemplary and non-limiting embodiments, a switch and a clamp mayprovide vehicle-side protection against potential failure modes. Forexample, if the vehicle side enters its Anomaly state, it may notify thesource which may subsequently enter its Anomaly state and may turn downor shut down the source power. In case the wireless link is down or thesource is unresponsive, the switch in the rectifier may open to protectthe battery system.

In an exemplary embodiment, an ADP could enter its Anomaly state inseveral ways. A few examples include:

-   -   The battery manager requests an emergency disconnect    -   The voltage clamp circuit is active for more than 3 seconds (or        some set period of time, potentially user settable and        reconfigurable)    -   The wireless communications link is down    -   The ADP does not update the watchdog timer in the rectifier        controller    -   A temperature, voltage, current, or other error-condition set        point is violated.

In an exemplary and non-limiting embodiment of a charging engagement,control-system information may flow across the following interfaces:

-   -   ASP-ADP: Wireless interface between the Application Source        Processor on the source side and the Application Device        Processor on the vehicle side.    -   ASP-Laptop: Wireless interface used to send a webpage with        source diagnostic information that can be displayed on a laptop        for demonstration, system configuration, and debug purposes.    -   ADP-Laptop: Wireless interface used to serve a webpage with        device diagnostic information that can be displayed on a laptop        for demonstration and debug purposes.    -   ASP-AmpCon: an I2C interface between the ASP and the amplifier        controller.    -   ADP-RectCon: an I2C interface between the ADP and the rectifier        controller.

In exemplary and non-limiting embodiments, the first interface (ASP-ADP)may be used to exchange the messages needed to support the exemplarySequence Diagram shown in FIG. 5. It may be that standardizationactivities will specify certain wireless communications protocols, suchas the IEEE 802.11p protocol and/or Dedicated Short Range Communications(DSRC) using a licensed band at 5.9 GHz. In exemplary and non-limitingembodiments that comply with standards, it may be that only certainwireless communications protocols will be supported by and used toimplement the wireless power system controls. In exemplary andnon-limiting embodiments not governed by standards, both known andproprietary wireless communications protocols may be supported by andused to implement wireless power system controls. In an exemplaryembodiment, a reconfigurable EV wireless power transfer system has beendemonstrated using the IEEE 802.11b unlicensed band (Wi-Fi) to implementthe system control commands and communication.

In exemplary and non-limiting embodiments, the second and thirddiagnostic interfaces may be for running demonstration purposes and toprovide diagnostic information in an easily accessible format. Theconnections with the laptop may also use 802.11b. A Wi-Fi enabled routermay be required for simultaneous support of wireless connections for theASP-ADP, ASP-Laptop, and ADP-Laptop. For demonstrations that onlyrequire the ASP-ADP connection, an 802.11b peer-to-peer connection couldbe used.

In exemplary and non-limiting embodiments, the fourth and fifthinterfaces may be between the ASPs, other system controllers, and dataloggers. Other system controllers may be implemented in physicallydistinct microcontrollers as described in the exemplary embodiment, orthey may be co-located in the same ASPs.

Some example interactions amongst the ASP, ADP, controllers and FODdetectors are described below. These are just some of the exampleinteractions, but in no way are the interactions contemplated by thisinvention limited to only the examples given below.

In an exemplary embodiment, an Application Source Processor (ASP) may bea microprocessor that holds the state information for the source side ofthe reconfigurable EV wireless power transfer system. Physically, it maybe implemented in a PIC-32 microcontroller. The software running on theASP may execute the state transitions described previously, as well asthe wireless communication with the vehicle side and potentially withthe diagnostic laptop (if present). It is anticipated that users maymodify or replace the software on the ASP and still operate thereconfigurable EV wireless power transfer system. Functional interfacesto the Application Source Processor may include, but may not be limitedto:

-   -   Wi-Fi link for communicating with the vehicle's ADP and for a        diagnostic display for user demonstrations, diagnostics and/or        customization (iPAD or laptop)    -   Serial Peripheral Interface (SPI) serial-link over Ethernet on a        2.4 GHz RF link for communicating with the vehicle's ADP    -   Hardware support for Universal Asynchronous Receiver/Transmitter        (UART) serial-link over Ethernet on a 2.4 GHz RF link for an        alternative method of communicating with the vehicle's ADP    -   Interface to amplifier controller    -   I²C for commanding and receiving status information    -   Interrupt for high-priority tasks (e.g. FOD detection, source or        vehicle anomaly)    -   Bi-directional watchdog/heartbeat signal    -   FOD detection interface    -   Metal object detector    -   Temperature sensors    -   Living being sensor    -   System process interlock inputs-used for higher-level        controllers that may need to shut down the source suddenly.    -   I²C interface to source side PIM (PCB Information Memory with a        unique identifier (UID), configuration settings, etc.)

In an exemplary embodiment, an ASP may have a Wireless CommunicationsLink Interface. For example, the source-side ASP may communicate withthe vehicle-side ADP over a wireless communication link. The wirelessprotocol may be implemented using TCP/IP over a 2.4 GHz Wi-Fi link. TheRF module may be IEEE Std. 802.11b compatible with a 4-wire SPIinterface to the ASP.

In an alternate exemplary embodiment, a communication interface usingthe ASP serial UART port may be available as an option. The serial portmight interface to an external wireless module to support the link. Astandard UART interface may provide the flexibility to use anyparticular wireless protocol that a user may want.

In an exemplary embodiment, there may be an interface between the ASPand the amplifier controller. An amplifier controller may providelow-level control of the source electronics, while the ASP may providehigh-level control and may be responsible for the execution of theoverall system charging cycle. The interface to the amplifier controllermay be presented as a set of control and status registers which may beaccessible through an I²C serial bus. Such an arrangement could supportuser customization of the control algorithms.

In an exemplary embodiment, there may be an interface between an ASP anda FOD detection subsystem. The ASP may be able to receive preprocesseddigital data from a FOD processor. A FOD processor may be designed toperform signal conditioning and threshold detection for the varioustypes of sensors connected to it. Upon detection of FOD, the FODprocessor may interrupt the ASP and transmit the FOD decision-circuitresults. The ASP may then take appropriate action (e.g. shut down thepower, go to a low-power state, issue a warning, etc.) The FOD processormay also transmit the pre-decision signal-conditioned data in digitalform to the ASP so that soft decision algorithms that use otherinformation can be implemented in the ASP.

In an exemplary embodiment, there may be an interface between an ASP anda System Interlock subsystem. An interlock interface may consist of aset of optically coupled digital inputs which may act as system enables.The interlocks may be externally generated signals which may be assertedto turn on the system. The interlocks may also be able to be used by theuser to shut down the system on command. The systems and signals thatfeed the external interlock signals (shutdown switch, additional FODdetection, infrastructure fault detection, etc.) may be applicationspecific.

In an exemplary embodiment, there may be an interface between an ASP anda Positioning and Alignment Interface. A positioning and alignmentinterface may communicate data from a vehicle alignment and positioningsensor to an ASP to determine whether sufficient wireless power transferefficiency may be achieved given the measured relative position ofsource and device resonators. If the resonators are not sufficientlywell aligned, the ASP may communicate to the device ADP and instruct thesystem to generate a message to the driver that the vehicle needs to berepositioned and to inhibit system turn-on until proper positioning isestablished.

In exemplary and non-limiting embodiments, there may be an interfacebetween an ASP and a Diagnostic/Debug subsystem. For the purposes ofdemonstrations, customization, and testing, a diagnostic/debug interfacemay be available across a wireless link between an ASP and a laptop, ortablet, or smartphone or any other processing unit that preferablycomprises a display. In some exemplary and non-limiting embodiments, thewireless communications connection may be through a dedicated Wi-Finetwork. In exemplary and non-limiting embodiments, the interface mayallow a laptop, or other external controller, to put the EV wirelesspower transmission system in a diagnostic and/or customization modewhere preset interlocks may be over-ridden and state changes may beforced onto the ASP.

In exemplary and non-limiting embodiments, this interface may also allowa laptop, or other external controller, with a Wi-Fi capability toaccess the ASP. For example, the ASP may be capable of streaming stateinformation to the laptop which may store it in a log file. Parametersthat can be stored in the log file may include:

-   -   Time-stamped events such as state changes, messages passed,        messages received    -   Measured voltages, currents, temperatures, and impedances that        are being compared to set points by the ASP or amplifier        controller.    -   Configuration information such as software/firmware versions,        hardware IDs, etc.    -   The log file should be able to be viewed on the laptop and        incorporated into a spreadsheet for later analysis.

In exemplary and non-limiting embodiments, an Application DeviceProcessor (ADP) may be a microprocessor that holds the state informationfor the vehicle side of an EV wireless power transfer system.Physically, it may be implemented in a PIC-32 microcontroller. Inexemplary and non-limiting embodiments, the software running on the ADPmay execute the state transitions described previously, as well as thewireless communication with the source side and the diagnostic laptop,or other external controller. Users may modify or replace the softwareon the ADP to customize the operation and control of an EV wirelesspower transfer system.

In exemplary and non-limiting embodiments, functional interfaces to theApplication Device Processor may include but may not be limited to:

-   -   Controller Area Network (CAN) Bus implemented on the physical        layer (PHY) on the device side for use with vehicle        communication, diagnostic equipment, and/or measurement and or        monitoring equipment    -   Serial-link over Ethernet on a 2.4 GHz RF link for communicating        with the Source ASP    -   Wi-Fi to a diagnostic display for user demonstrations and/or        customizations (iPAD or laptop)    -   Interface to a rectifier controller    -   I²C for commanding and receiving status information    -   Interrupt for high-priority tasks (e.g. FOD detection, vehicle        anomaly)    -   Bi-directional watchdog/heartbeat signal    -   System process interlock inputs used for higher-level        controllers on a vehicle that may need to disable the charging        cycle.    -   I²C interface to Device side PIM (PCB Information Memory with        UID, configuration settings, etc.)

In some exemplary and non-limiting embodiments, there may be aninterface between an ADP and a CAN Bus. In some exemplary andnon-limiting embodiments, the ADP may include a CAN bus interface. Inexemplary and non-limiting embodiments, software running on an ADP maybe augmented by a user to support a CAN bus interface even if theas-designed and/or as-delivered EV wireless power transfer system didnot include this functionality.

In exemplary and non-limiting embodiments, a vehicle-side ApplicationDevice Processor may have a Wireless Communications Link Interface. Forexample, a device-side ADP may communicate with the source-side ASP overa wireless communication link. The wireless protocol may be implementedusing TCP/IP over a 2.4 GHz Wi-Fi link. The RF module may be IEEE Std.802.11b compatible with a 4-wire SPI interface to the ADP.

In exemplary and non-limiting embodiments, there may be an interfacebetween an ADP and a rectifier controller. The ADP may communicate withthe rectifier controller over an interface that may be similar to theone between the ASP and the amplifier controller. A rectifier controllermay provide low-level control of the device electronics, while the ADPmay provide high-level control and may be responsible for the executionof the overall system charging cycle. The interface to the rectifiercontroller may be presented as a set of control and status registerswhich may be accessible through an I²C serial bus. Such an arrangementcould support user customization of the control algorithms. Theinterface may also consist of, an Interrupt Request input and a set ofuni-directional watchdog/heartbeat outputs.

In an exemplary embodiment, there may be an interface between an ADP anda Positioning and Alignment Interface. A positioning and alignmentinterface may communicate data from a vehicle alignment and positioningsensor to an ADP to determine whether sufficient wireless power transferefficiency may be achieved given the measured relative position ofsource and device resonators. If the resonators are not sufficientlywell aligned, the ADP may communicate to the source ASP and instruct thesystem to generate a message to the driver that the vehicle needs to berepositioned and to inhibit system turn-on until proper positioning isestablished.

In exemplary and non-limiting embodiments, there may be an interfacebetween an ADP and a System Interlock subsystem. This interface may beanalogous to that described between an ASP and a System Interlocksubsystem. It could be used by the battery manager to force a shutdownof the EV wireless power transfer system. For example, if the interlockis de-asserted, the ADP may enter its Anomaly state and may demand thatthe source shut down immediately and may open the switch in therectifier circuit. In the case of an unresponsive source or aninterrupted wireless communications link, the ADP may open the switchwithin 3 seconds, or an appropriate period of time, and communicating acommand that the source shut down.

In exemplary and non-limiting embodiments, there may be an interfacebetween an ADP and a Diagnostic/Debug subsystem. For the purposes ofdemonstrations, customization, and testing, a diagnostic/debug interfacemay be available across a wireless link between an ADP and a laptop, ortablet, or smartphone or any other processing unit that preferablycomprises a display. In some exemplary and non-limiting embodiments, thewireless communications connection may be through a dedicated Wi-Finetwork. In exemplary and non-limiting embodiments, the interface mayallow a laptop, or other external controller, to put the EV wirelesspower transmission system in a diagnostic and/or customization modewhere preset interlocks may be over-ridden and state changes may beforced onto the ADP.

In exemplary and non-limiting embodiments, this interface may also allowa laptop, or other external controller, with a Wi-Fi capability toaccess the ASP. For example, the ASP may be capable of streaming stateinformation to the laptop which may store it in a log file. Parametersthat can be stored in the log file may include:

-   -   Time-stamped events such as state changes, messages passed,        messages received    -   Measured voltages, currents, temperatures, and impedances that        are being compared to set points by the ADP or rectifier        controller.    -   Configuration information such as software/firmware versions,        hardware IDs, etc.    -   The log file could be viewed on the laptop and dumped into excel        for later analysis.

In exemplary and non-limiting embodiments of EV wireless power transfersystems, an amplifier controller may provide low-level control to aPower Factor Corrector (PFC) and a switching amplifier. The interfacesbetween an amplifier controller and other system components may include,but may not be limited to:

-   -   Interface to Application Source Processor        -   I²C        -   Interrupt        -   Bi-directional Heartbeat/Watchdog    -   PFC Hardware control interface    -   Amplifier hardware control interface    -   System critical interlock inputs    -   System On/Off

In exemplary and non-limiting embodiments of EV wireless power transfersystems, a rectifier controller may provide high speed monitoring ofrectifier power and system critical fault control. The interfacesbetween a rectifier controller and other system components may include,but may not be limited to:

-   -   I²C interface to Application Device Processor        -   I2C        -   Interrupt        -   Bi-directional Heartbeat/Watchdog    -   Rectifier hardware control/status interface    -   Fault indicators such as over current, over voltage, over        temperature, clamp circuit activated, etc.    -   Device side system critical interlock inputs.

An reconfigurable EV wireless power transmission system may bepartitioned into notional subsystems so that the interactions betweensubsystems may be studied and design decisions made be made as to whichcontrol functions and set-points may be customizable by a use whilestill ensuring safe, efficient and reliable performance of the system.One method to analyze the system performance impact of allowingcustomization and/or reconfigurability of the control architectureand/or algorithms and/or set-points is to perform a Failure Mode EffectsAnalysis (FMEA). A preliminary FMEA may comprise a prioritized listingof the known potential failure modes. FMEA may need to be an on-goingactivity as new system failure modes are identified.

In exemplary and non-limiting embodiments, an FMEA process that scorespotential failure modes in a number of categories may be used toidentify the severity of certain failure scenarios. Categories that maybe used to identify customizable parameters may include, but may not belimited to

-   -   Severity (1-10): If the failure mode occurs, how severe (SEV) is        the impact to system functionality, performance, or safety? A        score of 10 indicates a major hazard and a score of 1 indicates        a minor loss of performance or functionality.    -   Likelihood (1-10): How likely is the failure to occur? A 10        indicates almost certain occurrence while a 1 indicates a very        remote chance of occurrence (OCC).    -   Undetectability (1-10): How likely is it that the failure will        be detected (DET) and reacted to by the system during operation?        A 10 indicates that the control architecture is very unlikely to        detect the failure while a 1 indicates almost certain detection.

In exemplary and non-limiting embodiments, the potential failure modesmay be prioritized according to their Risk Priority Number (RPN)-whichis merely the product of their three category scores.

While the invention has been described in connection with certainpreferred exemplary and non-limiting embodiments, other exemplary andnon-limiting embodiments will be understood by one of ordinary skill inthe art and are intended to fall within the scope of this disclosure,which is to be interpreted in the broadest sense allowable by law. Forexample, designs, methods, configurations of components, etc. related totransmitting wireless power have been described above along with variousspecific applications and examples thereof. Those skilled in the artwill appreciate where the designs, components, configurations orcomponents described herein can be used in combination, orinterchangeably, and that the above description does not limit suchinterchangeability or combination of components to only that which isdescribed herein.

All documents referenced herein are hereby incorporated by reference.

What is claimed is:
 1. A wireless energy transfer system with asegmented control architecture, the system comprising: a wireless energytransfer system coupled to a primary controller; and a user configurablesecondary controller in communication with the primary controller;wherein the primary controller performs essential control functions forthe wireless system.
 2. The system of claim 1, wherein the essentialcontrol functions of the primary controller comprise maintainingwireless energy transfer operating safety limits.
 3. The system of claim1, wherein the essential control functions of the primary controllercomprise monitoring and controlling the voltage and current on energytransfer components.
 4. The system of claim 1, wherein the userconfigurable secondary controller allows adjustment of at least onenon-safety critical parameter of the system.
 5. The system of claim 1,wherein the primary controller and the user configurable secondarycontroller are each physically implemented on the same hardware.
 6. Thesystem of claim 4, wherein the user configurable secondary controller isconfigurable to adjust a maximum output power of the wireless energytransfer system.
 7. The system of claim 4, wherein the user configurablesecondary controller is configurable to adjust a frequency of thewireless energy transfer system.
 8. The system of claim 4, wherein theuser configurable secondary controller is configurable to adjust thesecurity of the wireless energy transfer system.
 9. The system of claim1, wherein the primary controller and the user configurable secondarycontroller are each virtual controllers implemented on the sameprocessor.
 10. The system of claim 1, wherein the primary controller andthe user configurable secondary controller are each separate processors.